Improvement in valve-gear for steam-engines



` UNITED STATES .PATENT OFFICE.

AUSTIN sEELr, or ALToN, ILLINoIs.

Specification'forming part of Letters Patent No. 78,764, dated June 9, 1868.

ToaZZ whom it may concern,.-

Beit known that I, AUSTIN SEELY, of Alton, in the county of Madison, and State of Illinois, have invented a new and improved Expansion-Engine; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to makeand use the same, reference being had to the accompanying drawings, forming part of this specifica-tion.

Figure 1 is a top view of cylinders.

Figure 2 is a vertical section of the same, through m', iig. 1.

Figure 3 is a side elevation ot" cylinders A, fig. 2. Y

Figure fl is a horizontal section of the two cylinders through the connecting-pipes and valve-chests.

Figure v is a detail perspective view ofthe cam-rod on the pin used for reversing the engine.

Figure 6 is a series of diagrams, showing the relative positions of. the valves and pistons.

Figure 7 is amodiiication of the pipecon nections.

Similar letters of reference indicate corresponding parts. y

My'invention consists in the arrangement of devices as will be hereinafter more fully described. y A A Engines have been constructed vwith auxilary expanding-cylinders, for using the steam at a lower pressure after it has driven the l addition to the valves just described, auxilpiston ina the iirst cylinder.` These have the exhaust side of the first cylinder communieating with the receiving or steam side of the auxiliary cylinder. A Y I In my improvement the receiving sides of both cylinders are connected, and a portion of the steam used in the rst cylinder is exhausted into the air in the usual way, and another portion by expansion Adrives the pistons of both cylinders, as will be shown. In 1854, B. F. `Day obtained Letters Patent, No. 11,119,for acompound engine using the steam expansively in two cylinders, connected as last described.

Slide-valves are used, and both cylinders receive steam from the same throttle, which presents a variable adjustment of the expanded steam.

Practical lfficulties in reversing and otherrender it incapable of successful application on boats, and my invention is designed to so,

improve, and substitute for some of its parts, improved devices, that the expansion of steam in two connected cylinders can be made available and practicable on boats or elsewhere.

To apply my improvements, two cylinders, A and B, figs. 1 and 2, are connected by the pipes C C, which open into the steam-chests of the two cylinders, as shownat figs. 2 and 4. The pistons of the two engines connect to the same shaft by cranks, at right angles with each other.

On the shaft are cams and yokes, of the usual construction for operating the valvegear of both cylinders. The cam-.rods connecting them with the rock-shafts are shown 'atf, c, and f', fig.. 1.

In fig. 1, the valves R R are the receiving or steam-valves, and E E are the exhaustvalves, of cylinder A. The first take steam `from the throttles T, through the side-pipe p', which opens into their valve-chests, and the second exhausts a portion of the steam used through the exhaust side-pipe p,leading to the escape-pipe 19.

These valves may be double orsingle pupi' pet-valves, of the ordinary construction, and

are operated by levers and lifters, as heretofore made.nothing new being claimed in their specific operation. These valves are shown in section at B. and E, fig. 2.

The steam-chests of cylinder A contain, in

iary valves V,'in separate chests, the ports of which open into cylinder A, and the valves, when lifted. an'd seated, open or shut off steam communication from the said cylinder. The pipes C C, connecting cylinders A and B, open into these valve chambers, just above the `valves V, as shown at fig. 2, and by the lifting of these valves, part of the steam within cylinder A escapes into cylinder B, and, by expansion, drives the piston of the latter.

The said valves, when seated, prevent the reaction of the steam into cylinder A at that end which is exhausting, andthe timely lifting of these auxiliary valves, to admit the steam into cylinder B, and again seating to .prevent the reaction aforesaid, is accom- 'plished by levers and lifters, operated by the `full-stroke cam-rod f, which also operates the exhaust-valves E E of the same cylinder, for the lifterl which raises the levers o e of the auxiliary Valves V V, and the lifter Z', which raises the levers c e of the exhaust-valves E E, are all loose lifters, and work With sleeves on the rock-shaft 7j, the latter carrying the fast lifter b, which receives its motion from a cut-off cam, by the rod c and pin m". Said lifter b raises the steam-valves R. The loose litters receive their motion from a full-stroke cam by the rod f, which vibrates a secondary rock-shaft, r r', communicating its motion to the loose lifters Z Z', by arms c1. a and links i' t', the latter being connected with arms a' a', attached to the said loose lifters.

Both of these rock-shaftsare-provided With outer arms and pins, for hooking on the calnrods cand f, to their respective rock-shafts, as Will be shown.

The valve-gear of cylinder B consists of a single rock-shaft, with fast litters, and an arm, h, with upper and lower pin, h h",to hook thereon a full-stroke cam-rod, f'. The valves are lettered R' R', E' E', and, together. with its levers and lifters, are of the ordinary construction, and are shown in figs. l and 2. The secondary rock-shaft r' r', on cylinder A, has

`a lever-arm, m, for Working the rock-shaft by hand, and upper and lower pins m m". fm" y is the pin on the cut-off rock-shaft r r.

The throttle-valve T admits steam to thereceiving-valves R R, by means of a pipe, t', leading from it to the side-pipe p'. A similar throttle valve, T', admits steam to the By this means the engineer is enabled toy increase the power of the auxiliary cylinder Aat will, When it is lnecessary to do so, for the regular action of the valves on cylinder B does not interfere With the continuous pressure of the steam through T', as will be shown. This arrangement of a second-throttle is of great advantage, for the current around river bends, and in other places, is often very strong, requiring the full power of the engines to be exerted. in propelling a boat against it.

When the steam is admitted through both throttles, a variable expansion is the result, and this can be controlled and regulated by the amount admitted through either throttle, or by entirely closing one of them.

The relative action of the valves of both cylinders is shown in the skeleton diagrams, fig. 6. As the action of the valves at both ends ofthe cylinders is identical, those of 011e end only Will-be shown, together with the f relative position of the pistons T.

In Diagram I, 4the piston A is up, .pist-on B at thecentre, and going up, the valves E R V R' are seated, E' being up, and the crank of B on its upper half centre.

Diagram II. The piston A begins'to descend, valves R and V lifting together. A takes steam for the down stroke, through R,

and steam also iills the pipe C, stopping at ders, driving piston A to the bottom, and pis-v y ton B to the centre, and-its crank to the lower half centre.

The same action then follovvs` at the other ends of the cylinders, so that While the piston of A is Ydriven by expanded steam, the greater portion of its stroke each Way, that oil B is wholly driven by expanded steam, unless the throttle T is opened, in which case the pressure in both cylinders is equally aug- :mentedl To prepare' this engine'for reversing, ship the full-stroke rod f on its reversing-pin Vm",

then throttle T being closed an-d T' opened, 4the valves R become neutral, the valves V acting as receiving-valves.

, The cut-off cam-rod need not therefore have a hook, but be provided with a strap-joint, as shown at fig. 5.

For reversing cylinder B, shipthe rod f onl gines ,expansively, T' is closed and T opened.-

When using throttle T alone, the valves R R becomeneutral, being simply lifted and seatedwithout admitting steam, and to prevent the pressure from Within the cylinder from raisingY the said valves and their levers, the former" are iittedvwith a slight slip on their stems, just suficient to admit the steam to the space-above thevalve, thus preventing the raising of their stemsjand levers.

A similar. slip maybe given to thevalves V V for the same object. By means of the double throttle the expansion of steam may be varied between the maxima and minima extremes.

The cost of my engine will be no greater than that of the common ones of equal nominal horse-power now used on stern-Wheel` boats, and will bean improved substitutefor the same by connecting the cranks at each end of the Wheel With one cylinder.

By this arrangement of an auxiliary cylinder, I propose ,to expand steam to ten Volumes, which give an effect, in proportion to that of a half-,stroke cam, ask 31 to 17, nearly I have contemplated Various modications of the valve-gear of my engine, each of which having;

Would be attended with certain advantages. For example, in the valve-gear of cylinder A, the positions of the rock-shafts could be reversed, also the cams on the main. shaft, which Would connect the full-stroke rod With the rock-shaft now shown at r fr". This Wouldnecessitate the lapping of one pair of full-stroke levers; there would then be tWo tight lifters and one loose one, the reverse of the present arrangement. Again, by connecting the full-stroke rods to common links,

the operation of reversing Would be reduced to the simple motion of raising and lowering the same.

To obviate the filling of both pipes C each timethe steam is admitted by the valves R, a modification of the pipe-connections may be made, as shown at g. '7, in the red diagram, Where T and T are additional throttlevalves, one on each side ot' the main throttlevalve T.

The connections are made as shown, t being the pipe connecting the three throttles. ,z is the opening for the steam-pipe. From the boiler p p are short pipes, leading to the valvechambers V V. -t is a Vshort pipe leading from the chamber of the throttle-valve T to the receiving sidepipe p.

By this improvement, when valves Tl and T are closed, the steam is admitted to the pipe C alternately, and only When the valves V rise from their seatsB This arrangement dispenses With the sidepipe p, connecting the chambers of the valves V, as shown in the other figures. When the throttle-valves T T are opened, the steam from the boiler then augments the expansion of steam in the cylinder B,and consequently equalizes the pressure in both cylinders.

This improvement Will be found to economize the steam by lessening the radiation and condensation which take place when both the pipes C are kept iilled.

The shaded drawing at iig. 7 exhibits another and preferable manner of arranging the connections of the three throttle-valves. In this modification, the valves V V are connected by the side-pipe p, and the receiving side-pipe p dispensed with, the throttles T y and T being` situated in a pipe connecting the three throttles, as shown in the drawings at tig. '7. From this pipe, short pipes t connect with the receiving-valves R R, and a single short pipe t connects the side-pipe p, of the valves V V, with the pipe connecting the three throttles, as shown. z is the point of junction of the steam-pipe from the boilers.` In this iigure the elbow-pipes, shown in the red diagram, are employed to connect the -throttles T T With the receiving-valves, and

the single throttle, T, is used to admit steam from the boiler tothe auxiliary cylinder B. The valves T and Tare closed when the engine is backing, thus rendering the receiving-valves R R neutral, as before mentioned.

This arrangement I' consider preferable to tially as and for the purpose shown and de-n scribed.

3. The additional throttle-valves T T ar" ranged in the pipe-connections, substantially as shown, and for the pur ose specified.

\ USTIN SEELY.

Witnesses:

FRANK H, FERGUSON, J, T, Rios. 

